By the time most women reach 30, they naturally begin to lose muscle mass.  By the end of your 40’s, inactivity and poor nutrition can result in the loss of as much as 10% of your lean body mass.  By 65, that number could be closer to 20%. (1)

Losing muscle mass can be detrimental to your health for a number of reasons.  Losing lean mass lowers your metabolism making it easier to gain body fat and more difficult to lose it.  Putting on excess body fat ultimately increases your risk of a number of health conditions, such as diabetes and heart disease.

The loss of lean body mass can also decrease your strength and mobility, making everyday tasks more difficult to perform.  Over time, it also increases your risk of injury — weak muscles and bones equate to more sprains, strains, and fractures.  

So for women, building muscle after 40 doesn’t just have to be about recapturing how you looked in your 20’s, it can also be a proactive means of maintaining your health as you age.   

Can Women Build Muscle After 40?

Building muscle is very dependent on hormones, particularly testosterone. (2) Women’s testosterone levels are typically around 10x lower than men’s, which is why on average, women tend to have less muscle mass compared to men.  

Your hormone levels at age 40 are usually lower than they were when you were 20.  Most physicians would consider these levels normal, but they may not be optimal and may affect muscle loss and body fat distribution.

In addition, to shifting as you age, your hormonal levels change even further with menopause, which occurs between the ages of 45 and 55 for most women. (3) Diminishing levels of hormones like GH and DHEA can make you more vulnerable to muscle loss.

While the aging process can make building muscle more challenging after 40, it’s far from impossible.  In fact, with the right diet and training regimen in place, just about anyone is capable of doing it.          

How Does Aging Affect Your Diet?  

Protein Intake

When it comes to maintaining, let alone building muscle mass, one of the most important components of your diet is protein.  Your muscles are made up of proteins, which are constantly going through states of being broken down and rebuilt.

Muscle loss occurs when more proteins are being broken down in your body than rebuilt.  The process through which your body rebuilds muscle tissue is known as muscle protein synthesis (MPS).  

In order to build muscle, your body must synthesize more protein than it naturally breaks down over the course of a day.  For that to be a possibility, you need to have an adequate supply of dietary protein.

As you age, your body will require more dietary protein to keep your levels of MPS elevate. (4) Middle-aged women on average require 10 – 15 more grams of protein per dose to see the same levels of MPS observed in younger adults.

How Much Protein Should Middle-Aged Women Consume Per Day?

The RDA for protein is 0.8g per 2.2lbs (1kg) of body weight for women 20 years and older.  But this basic recommendation doesn’t take into account the effects that aging can have on your body’s protein needs.  Research suggests that increasing your dietary protein intake as you age decreases the likelihood of muscle loss later in life. (5)

A number of studies have investigated what the optimal protein intake is for middle-aged women.  While there is some variation, most findings suggest that somewhere between 1.4g to 2.0g of protein per 2.2lbs (1kg) of body weight is the optimal range for maintaining your lean body mass as you age.     

Calorie Intake

As we’ve already discussed, aging can naturally cause the loss of lean muscle mass in sedentary women.  This ultimately reduces your calorie demands because your body requires fewer calories to maintain fat compared to muscle.  

That means that if you’re in your 40’s and haven’t been actively engaging your muscles, your body will likely require fewer calories to maintain your weight compared to when you were younger. (6)

Having less muscle mass to maintain, in turn, makes overeating that much easier when you’re middle-aged.  

The residual effects of having kids, as well as the aging process itself, often leave women in their 40’s with some excess body fat they would like to lose.         

So How Many Calories Do You Need To Shed Fat and Build Muscle?

In order to lose weight, you need to be taking in fewer calories than your body burns off in a day.  But in order to do so, you need to know how many calories it actually takes to maintain your current weight, which is known as your total daily energy expenditure (TDEE).  You can easily estimate your TDEE using an online calculator.  

Once you have a good idea of what your TDEE is, you can start subtracting calories from your daily diet to create a deficit but don’t go overboard.  Stick with a moderate deficit of between 250 – 500 calories. If you restrict your calories too much, you’ll not only lose fat, you’ll also lose muscle mass.  

Benefits of Weight Training For Women Over 40

Maintain or Build Lean Muscle Mass

For women over 40, there’s a pretty simple rule when it comes to your muscles: you have to use them or you’ll lose them.  While your nutrition is certainly an important part of the picture, in order to maintain, let alone build muscle mass as you age, you need to be lifting weights.

As we’ve already touched on, your muscles are constantly going through a state of being broken down and rebuilt.  Your muscles grow when the amount of protein synthesized within them eclipses the amount that is broken down.

Weight training actually causes microscopic damage to your muscle tissue and in order to repair the damage, your body’s levels of MPS are increased for up to 48 hours.  In combination with an adequate supply of dietary protein, lifting weights is an incredibly effective means of maintaining and even build muscle mass for women over 40. (7)

Change Your Body Composition

As you age and lose muscle, your metabolism decreases because it takes fewer calories for your body to maintain fat compared to lean muscle mass.  So, even in cases where a person’s weight doesn’t dramatically change as they age, their proportion of body fat to lean muscle mass will likely still increase.  

Weight training, however, can help you to reshape your body composition by increasing your proportion of lean muscle mass.  In addition to increasing your levels of MPS, which is the primary means through which you build muscle, lifting weights also helps to burn fat.  

Resistance exercise causes fat oxidation in your muscles, which is a process through which your muscles burn up free fatty acids to create energy.  Building muscle and shedding fat ultimately increase your body’s metabolism over time, meaning that you’ll be able to consume more calories without the risk of gaining unhealthy weight.  You’ll also look and feel more fit.

Reduce the Risk of Musculoskeletal Injury

As you age, you’re at an increased risk of losing lean mass like muscle and bone, which can reduce your strength and mobility, increasing the risk of musculoskeletal injuries likes sprains, strains, and fractures.  

By the time you reach 65, if you’ve remained sedentary for most of your adult life, everyday tasks like walking up or down a flight of stairs can become far more challenging and dangerous.

Resistance training, however, can help you build strength and mobility in your muscles, tendons, and joints as you age. (8) Several studies have also shown that lifting weights helps to maintain and even increase bone mineral density in aging women. (9)(10)

Maintain a Healthy Hormonal Balance

As you age, your hormonal levels change.   Certain hormones like growth hormone (GH) become diminished in women over 40, which increases the risk of muscle loss.   GH plays an important role in your body’s ability to rebuild and repair damaged muscle tissues.  Lifting weights helps to increase the production of GH in middle-aged and post-menopausal women.  

Additionally, resistance training also helps to increase levels of the hormone DHEA in women over 40. Increases in DHEA levels have been found to be closely correlated with increases in lean body mass and bone mineral density in older women. (11) DHEA is associated with increases in lean body mass, bone density, and quality of life. The same increases have not been observed with endurance exercise. (12)

What Sort of Weight Training Should Middle-Aged Women Do?

Whether it’s CrossFit, powerlifting, bodybuilding or some other variant, all sorts of different approaches to weight lifting can be effective for getting fit and lean after 40.  However, the training methodology that is going to be right for you is ultimately going to depend on your goals.

Are you primarily looking to get stronger?  If so, maybe strength training is right for you.  What if you’re interested in improving both your endurance and your strength?  If that’s the case, maybe you’d be most interested in CrossFit.

Or maybe, what you want most is to recoup some of the muscle mass that you’ve lost over the course of the aging process.  Since this article is all about building muscle after 40, we’re going to focus our discussion on hypertrophy training.  

It’s important to point out that it’s definitely not the only way to build muscle but it’s among the safest and most effective, especially for those with little to no prior training experience.

Hypertrophy Training for Women over 40

The primary goal of hypertrophy training is to increase your muscles’ size.  However, many people will likely experience increases in strength over the course of their training as well.  

Compared to other styles of weight lifting, your muscles spend more time under tension with hypertrophy training.  That means you may be lifting lighter weight but you’ll be doing more sets and reps. Each training session will usually range from 9 – 16 sets, with each, generally consisting of between 8 and 12 repetitions.  Many training programs will require that some of those sets go to failure.

Increasing the time under tension causes more damage to your muscles.  Over time, your muscles adapt to this kind of stimulation by increasing in size to the better handle the demands of the exercises you’re doing.  

Any reputable hypertrophy-based training program will entail a full-body training split, meaning that you are engaging all of your body’s major muscles groups on a regular basis.  For most people, that equates to 3 – 5 days a week of training. If you’re only working out certain body parts, you’re more likely to develop imbalances and injuries in the muscles you’re not targeting, which is exactly to kind of thing we want to avoid, especially as we age!  

Sample Weekly Training Split For Women Over 40

Day 1: Back and Biceps
Day 2: Shoulders and Core
Day 3: Rest
Day 4: Legs
Day 5: Rest
Day 6: Chest and Triceps
Day 7: Rest

Wrap Up

While the aging process can affect your body composition, there are plenty of things you can do to avoid losing muscle mass as you get older.  On the nutritional side of things, a high protein intake is vital for maintaining muscle mass, especially for women 40 and over.

It ‘s also important that you’re regularly exercising if you want to maintain, let along build muscle mass as you age.  Numerous studies have demonstrated weight training to be an effective tool for mitigating age-related muscle loss in women. You don’t have to get too crazy in the weight room either. For most people 3 – 5 training sessions per week should give your muscles plenty of stimulation, while also giving them enough time to rest.